无法使用jquery AJAX进行跨源资源共享请求

Question

i am Trying to upload image to some External URL. I am getting Cross-Origin Request Blocked in the console. My response contains complete JSON data.

I have got a form with enctype="multipart/form-data". And this is my ajax

 $.ajax({
    url: 'externalURL/image/upload'
    type: 'POST',                               
    cache: false,
    processData:false,
    crossDomain: true,                                                          
    dataType : 'jsonp', 
    jsonpCallback: 'jsonCallback',
    data: $("#multiform").serialize(),  
    beforeSend: function (xhr)
    { 
        xhr.setRequestHeader("Content-Type","application/json");
        xhr.setRequestHeader("Accept","text/json");
    },
    error: function (xhr, status) {
        alert(status);
    },
    success: function (result) {
        alert(result);  
    }
}); 

I am getting error alert , when i try to upload.